The dark grey does look good with LCD. It hides pretty much everything under it except the actual display image. However, direct sunlight will give you some pretty bad glare and make it very hard to see the screen. This is probably also true in other bright environments like offices, etc.
If light is an issue, get the lighter grey. It still looks very nice. You need to take extra care with your bezel and such, since obviously you can see through it the glass easier, and it will show more flaws, if any.
You also want to factor in how it will fit into your design. For example, you wouldn't want to spend a lot of time and money on finishing some exotic wood and then hide it with the dark grey.